1. Field of the Invention
The invention relates generally to a medical handpiece and, more specifically, to an angled dental-medical handpiece.
2. Description of Related Technology
In the case of a so-called angled handpiece concerned here, it is known, for simplification of the drive shaft, in particular of the forward drive shaft section, to transversely divide the shaft of the handpiece and connect the divided sections with one another. DE 32 27 417 A1 shows a dental-medical angled handpiece having a shaft which is transversely divided in the region of the shaft angling. In contrast, DE 44 17 810 C2 shows an angled handpiece, the shaft of which is transversely divided behind the working head, whereby the shaft in the region of the angling is formed in one piece. These divisions make possible accessibility, in particular to the forward shaft section, from the fore (DE 44 17 810 C2) or from the rear (DE 32 27 417 A1) in relation to both production measures and also installation measures. In the case of the handpiece of DE 44 17 810 C2 there further extends, in the rearward end region of the handpiece, a delivery line for a medium, passing to the outside through the peripheral wall of the handpiece, outwardly to a hose connection.
In handpieces of this type it must be taken into account that there is needed not only the ability to insert handpiece parts to be installed, in particular the forward drive shaft section, but also the need for axial fixing, in order to attain good mounting and long working life.
The above-mentioned problem does not present itself in the case of so-called turbine handpieces, having a turbine drive in the region of the working head, because in the case of a turbine handpiece the production and installation of a construction for drive shaft mounting is not needed and there is only the need to provide longitudinally running channels for the delivery and discharge of compressed air to the turbine. Thus, in the case of a turbine handpiece, a one-piece configuration of the shaft in the region of the angling or in the region between the forward shaft section and the working head is not problematic.
DE 102 08 692 A1 shows a medical handpiece whose shaft and working head are illustrated in one piece, but here there is involved a simplified illustration without indication of the necessary construction elements for the bearing and mounting of the drive shaft, in particular of the forward shaft section. In reality, there is needed also with this angled handpiece at least one transverse division, in order to allow production and assembly.